SV40 associated miRNAs are not detectable in mesotheliomas

Our plain-English summary of SV40 associated miRNAs are not detectable in mesotheliomas, by G.V. Gee, M.L. Stanifer, B.C. Christensen, et al (British Journal of Cancer, 2010).

The study

• Authors: G.V. Gee, M.L. Stanifer, B.C. Christensen, W.J. Atwood, D. Ugolini, S. Bonassi, M.B. Resnick, H.H. Nelson, C.J. Marsit, K.T. Kelsey
• Journal: British Journal of Cancer
• Published: 2010;103(6):885-8
• Cited by: 14 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Simian virus-40 (SV40) is a DNA tumour virus that was introduced into the human population with contaminated poliovirus vaccine, and its role in mesothelioma is widely debated. PCR based testing has been called into question, as false positives can be because of cross-reactivity with related viruses, or to laboratory contamination. The Institute of Medicine has recommended the development of more sensitive and specific tests to resolve this controversy.

Methods: We have characterized highly sensitive RT-PCR based assays that are specific for SV40-encoded microRNAs (miRNAs), as an alternative to current testing methods.

Results: Using this sensitive and specific detection method, we were unable to identify SV40 miRNA expression in human malignant pleural mesothelioma (MM) samples.

Conclusion: Our work indicates that SV40 miRNAs are not likely to contribute to mesothelioma tumourogenesis, but highlights the value of this approach when compared with the relatively unspecific current testing methods.

In plain English

This was a laboratory study. It asked whether small RNA molecules (microRNAs) made by simian virus 40 (SV40) could be found in mesothelioma tumours. SV40 is a monkey virus that entered the human population through contaminated polio vaccine. The study did not look at asbestos exposure. The authors built tests for five SV40 microRNAs and checked them against synthetic RNA and cell lines. In human embryonic kidney cells infected with SV40, the tests first found one viral microRNA (called 3′) 48 hours after infection, and the level rose up to 96 hours. The authors then tested samples from multiple tissue banks: 94 human malignant mesothelioma tumour biopsies, 20 lung adenocarcinoma biopsies and 28 non-malignant biopsies. They found no SV40 microRNA in any human tissue sample. The authors concluded that SV40 microRNAs are not likely to contribute to mesothelioma development. They wrote that this can imply the virus itself does not contribute. They also gave another interpretation: only the virus's early genes are needed to transform cells. They stated that they could not completely exclude an association between mesothelioma and a transforming form of SV40.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Laboratory study developing and testing assays for SV40-encoded microRNAs, then applying them to banked human tissue samples
• Who was studied: 94 human malignant mesothelioma tumour biopsies, 20 lung adenocarcinoma biopsies and 28 non-malignant control biopsies, from multiple tissue banks in Italy and the United States. Collection dates were not reported. Laboratory cell lines were also used.
• Exposure: Simian virus 40 (SV40), detected through SV40-encoded microRNAs. No asbestos exposure was studied.
• Main results:
  • In SV40-transformed mouse and human cell lines, which are not expected to make the microRNAs, both the 5′ and 3′ assays gave background detection of less than 1% of the control.
  • In human embryonic kidney cells infected with SV40, the 3′ microRNA was first detected 48 hours after infection.
  • In the same infected cells, the 5′ microRNA was not detected at any point over 96 hours.
  • No SV40 microRNA was detected in any human tissue sample, including the 94 mesothelioma samples.
  • To rule out technical failure, the authors tested for three host-encoded microRNAs in mesotheliomas compared with non-malignant lung tissue. These data are in a supplementary figure that is not included in the text.
• The authors' conclusion: The authors concluded that mature SV40 microRNAs are not detected in human tissue samples, indicating that they are not likely to contribute to mesothelioma development.
• Limitations the authors state:
  • The authors could not completely exclude an association between human mesothelioma and a transforming form of SV40.
  • The assays could not tell the shortest 5′ and 3′ microRNAs apart from their longer variants.
  • Patient age data were not available for all samples.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: SV40, Mesothelioma, Pleural Mesothelioma.

Related studies

• Downregulated microRNAs in the differential diagnosis of malignant pleural mesothelioma — G.V. Gee, D.C. Koestler, et al. (2010)
• CDKN2A, NF2, and JUN are dysregulated among other genes by miRNAs in malignant mesothelioma -A miRNA microarray analysis — M. Guled, L. Lahti, et al. (2009)
• Identification of miRNA-103 in the cellular fraction of human peripheral blood as a potential biomarker for malignant mesothelioma--a pilot study — D.G. Weber, G. Johnen, et al. (2012)
• Plasmatic extracellular vesicle microRNAs in malignant pleural mesothelioma and asbestos-exposed subjects suggest a 2-miRNA signature as potential biomarker of disease — T. Cavalleri, L. Angelici, et al. (2017)
• Deregulation of miRNAs in malignant pleural mesothelioma is associated with prognosis and suggests an alteration of cell metabolism — C. De Santi, O. Melaiu, et al. (2017)
• Two Different Serum MiRNA Signatures Correlate with the Clinical Outcome and Histological Subtype in Pleural Malignant Mesothelioma Patients — M. Lamberti, R. Capasso, et al. (2015)

Browse more research in British Journal of Cancer, or return to medical research.